HD66730 Datasheet, PDF (22/131 Pages) Hitachi Semiconductor – Dot-Matrix Liquid Crystal Display Controller/Driver Supporting Japanese Kanji, Korean Font Display

HD66730/HD66731
Liquid Crystal Display Driver Circuit
The liquid crystal display driver circuit of HD66730 consists of 26 common signal drivers and 71 segment
signal drivers. HD66731 has 54 common signal drivers and 119 segment signal drivers. When the liquid
crystal driver duty ratio is set by a program, the necessary common signal drivers output drive waveforms
and the remaining common drivers output non-selected waveforms. In addition, drivers can be expanded on
the common and segment sides through register settings.
Display pattern data is sent serially through a shift register and latched when all needed data has arrived.
The latched data then enables the LCD driver to generate drive waveform outputs. This serial data is sent
from the display pattern that corresponds to the last address of the DDRAM and is latched when the
character pattern of the display data corresponding to the first address enters the internal shift register.
Booster
The booster outputs a voltage that is two or three times higher than the reference voltage input from pin
Vci. Since the LCD voltage can be generated from the LSI operation power supply, this circuit can operate
with a single power supply. Refer to Power Supply for Liquid Crystal Display Drive for details.
Oscillator
The HD66730/1 performs R-C oscillation by adding a single external oscillation resistor. The oscillation
frequency corresponding to display size and frame frequency can be adjusted by changing the oscillation
resistor. Refer to Oscillator for details.
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